Definition

Understanding Veins

Choose a preferred language

The ongoing flow of blood from the heart to the body and back to the heart again is called circulation. Blood vessels carry blood throughout your body. Veins are the vessels that return blood to the heart.

Front view of body showing arteries, veins, heart, and closed circulation system.


3 types of veins

  • Superficial veins collect the blood just beneath the skin.

  • Perforating veins carry blood from the superficial veins to the deep veins.

  • Deep veins run through the muscles and carry 90% of the blood back to your heart.

Section of skin and muscle showing deep, superficial, and perforating veins.


Anatomy of a vein

Veins have cup-like flaps called valves spaced along their inside walls. Valves open upward, so blood can move up the vein. Valves close to keep blood from falling back down the vein.

Cross section of muscle and vein showing open valve. Arrow shows blood moving up.Cross section of muscle and vein showing closed valve. Arrow shows blood moving up.

© 2000-2026 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Start your journey toward better health

Select a primary care physician who will deliver personal care, close to home.

Find a Doctor

We have more than 4,500 specialty care physicians in our network

We have you covered from head (neurosurgery) to toe (podiatry.) And everything in-between!

Find a Doctor

Need Help?

Get the right care at the right time.

Learn More
Related Articles
Read article
Heart Health
Understanding Circulation

Nonstop flow of blood from the heart to the body and back to the heart again is called circulation. Blood vessels are hollow muscular tubes that carry blood throughout your body, much like pipes circulate water in your home.

Read article
Heart Health
Discharge Instructions for Varicose Vein Surgery

You had a procedure in which your varicose veins were surgically removed. Here's what you can do to help with your recovery after surgery.

Read article
Heart Health
Understanding Chronic Venous Insufficiency

Problems with the veins in the legs may lead to chronic venous insufficiency (CVI). CVI means that there is a long-term problem with the veins not being able to pump blood back to your heart.

Read article
Heart Health
Discharge Instructions for Carotid Artery Stenting

After a carotid artery stenting procedure, you'll watch your incision site for bleeding and take all medicines exactly as prescribed. You'll take it easy. But try to get back to your normal routine as much as possible.